For BFL13 et al... FLA vs AGM vs Li vs heated Li

Gjac wrote:
I realize everyone on here has different electrical req's with how they camp. I don't fulltime and don't camp in the winter and have minimal electrical req's. I dry camp don't watch TV or play on the internet, so basically some lights, refer, WH, and water pump. He kept talking about real world experience and did 20 amp discharge test down running MV's to 8 amp tests and then concluded that LI was cheaper over the life cycle of battery usage. What I would have rather seen was low amp draws "real world" how I use my batteries and how long each battery would last. At $900/ battery for lithium and $90 for 6v flooded that is 10 times the cost. Will the LI's last 10 times longer to recover the initial cost?

No fair using your brain! :( You must realize that questioning LFPs on this Forum unless you already have them, is like your mother commenting on your new bride's prison tattoos.

I realize everyone on here has different electrical req's with how they camp. I don't fulltime and don't camp in the winter and have minimal electrical req's. I dry camp don't watch TV or play on the internet, so basically some lights, refer, WH, and water pump. He kept talking about real world experience and did 20 amp discharge test down running MV's to 8 amp tests and then concluded that LI was cheaper over the life cycle of battery usage. What I would have rather seen was low amp draws "real world" how I use my batteries and how long each battery would last. At $900/ battery for lithium and $90 for 6v flooded that is 10 times the cost. Will the LI's last 10 times longer to recover the initial cost?

Inappropriately high temperature degrades battery longevity with an alarming acceleration.

Here's a rude, crude, dangerous, but understandable example...

Stick a finger in a beaker of H2S04 sulfuric acid then extract

At 40F the acid will start to burn the skin as it heats up

At 120F you don't want to know. Yes it is that ugly.

It's the same with caustic soda.

This is why I wash lead acid battery corrosion with baking soda, boiling hot water, gloves and goggles. The amplification is to say the least, dramatic.

It is in the best interest of any battery's longevity to have it live in the lower 1/3rd of its Goldilocks' zone

The highest performance is gained in the highest 1/3 of its Goldilocks zone.

Temperature compensation is critical with any battery.

But realize as upper and lower temperature thresholds are approached the voltage and amperage limit issues are not yes/no black and white. They are graduated in effect.

Temperature values taken at electrical post connections give a good clue as to what is happening in the interior. Thermal conductivity is related to electrical conductivity because of electrical conductivity. Pathways are high amperage. Excessive temperature differential between cells is an emergency grade shutdown alarm.

“ There are somethings with lfp a person should be aware of and if proper homework is done and common sense is used a person should be able to enjoy the benifit of lfp, they are not faberge eggs some make them out to be.”

Well said Sir, a timely bit of ‘reasoned truth’ that would make even Diogenes Proud !!

3 tons

pianotuna wrote:

theoldwizard1 wrote:

pianotuna wrote:
What about hot weather testing? Damage on LiFePo4 starts at 86 f, and they should not be charged when the temperature is 113 f.

Lead acid batteries don't like prolong high temps either. Definitely shortens their life.

True, however lead acid can be used at 140 f and charged at 120 f--that's a far cry from 86 to 113 f for LiFePo4. There is no question that higher temperatures reduce lifespan.

However, does the BMS for the LiFePo4 shut down charging at 113 f?

The bms will do whatever it's programed to do. Can't speak for every manufacturer out there but here is an example of mine.

GBS Elite CPU/ EMS will disconnect the charge source or loads.
**Over voltage (highest cell is over 3.8V after a 3 second delay)
** Under voltage (lowest cell is below 2.8V after a 30 second delay)
** Over current (current exceeds 10C for 10 seconds)
**Over temperature (highest cell exceeds 150°F or 65°C)
**Under temperature (lowest cell is below 32°F or 0°C, charging is not allowed)
**Ground fault (There is a high voltage leakage greater than 2mA to the chassis pin)
**Unmanaged cells (The programmed number of cells does not equal the number of cells read)

I have been in temps from near 0f to 115f degrees. Reviewing my notes for the past years my highest cell temp has been 84f even when the front compartment was in the mid nineties. Cell temps rise and fall from morning to night and not drastically as one would think by reading comments in posts. From my experience I'll see cell temp rise when charging at 100a after a couple hours and when nearing full before switching to absorb stage, once this period of time completes the cell temps actually cool down some not hang at the high temps.

There are somethings with lfp a person should be aware of and if proper homework is done and common sense is used a person should be able to enjoy the benifit of lfp, they are not faberge eggs some make them out to be.

Quoting web pages isn't really homework unless they have their source posted to see where they're getting the info from. White page as best but then that takes time. Most folks like to be spoon feed and then take it a gospel. ;)

theoldwizard1 wrote:

pianotuna wrote:
What about hot weather testing? Damage on LiFePo4 starts at 86 f, and they should not be charged when the temperature is 113 f.

Lead acid batteries don't like prolong high temps either. Definitely shortens their life.

True, however lead acid can be used at 140 f and charged at 120 f--that's a far cry from 86 to 113 f for LiFePo4. There is no question that higher temperatures reduce lifespan.

However, does the BMS for the LiFePo4 shut down charging at 113 f?

MEXICOWANDERER wrote:
Lasts four times as long?

Warranty half as long?

Ever see Herb's face when Jennifer detailed what she was going to let her date do to her?

The Show was a masterpiece of BS sales parody

Mex, good that you are following all this! Yes, I enjoyed the program at the time, but did not appreciate how clever it really was. Now I wish "if only I knew then what I know now" and all that.

I will try that meter on the battery-engine block trick later when I get the gizmo and report back in that thread. Looks like next week after checking out the seals in the herring run up-Island (priorities!)

pianotuna wrote:
What about hot weather testing? Damage on LiFePo4 starts at 86 f, and they should not be charged when the temperature is 113 f.

Lead acid batteries don't like prolong high temps either. Definitely shortens their life.

BFL13 wrote:
I think the energy advantage has to do with the high discharge rate of LFPs but not clear on that.

IMO a good case for LFPs can be made for some scenarios without all the silly stuff.

Hi,

I am going guess they chose the "high amp" discharge rate of 80 amps, quite carefully, as a "sweet spot" for the LiFePo4.

Let's see what happens when 2 LiFePo4 have 185 amps drawn from them to power a microwave? Oh...but they didn't bother to test the Li--only the AGM's. (or did I miss that part???) Could that be a bit of an oversight? Or was it deliberate? Being a doubting Thomas I vote for "the man behind the curtain".

https://youtu.be/qdxG4P5zePc WKRP (for Mex)

There is no doubt that Li are coming and yes, an excellent case can be made for them. But I'll never ever have ANY large capacity secondary battery in my living quarters.

Lasts four times as long?

Warranty half as long?

Ever see Herb's face when Jennifer detailed what she was going to let her date do to her?

The Show was a masterpiece of BS sales parody